Asked why he was taking up the mantle for Stephen, Manford said: ‘Talk about inspirational. Some of the stuff he is coming out with for a lad of 19 was amazing. He wasn’t even bitter about having a short life. It was like he wasn’t angry he was having to leave the party early – he was just happy that he’d been invited.’

A host of other celebrities, including broadcasters Clare Balding and Phillip Schofield, chef Raymond Blanc and comedian Jimmy Carr, also urged their followers to donate to the appeal.

After hearing he had surpassed his £1million target yesterday, Stephen, of Burntwood, Staffordshire, tweeted: ‘But seriously… Wow, just wow. Thank you all so much.’

Stephen was diagnosed with colorectal cancer in 2010, aged 15. Despite having a tumour removed, it returned a year later.

When doctors told him his disease was terminal, he drew up a bucket list and shared his story on social media.

Siobhan Dunn, chief executive of the Teenage Cancer Trust, said: ‘Stephen is making the biggest possible difference to the young people who need our help. We’re a relatively small charity and this is a remarkable amount which will help us support many more young people with cancer.’